Information disclosure in parse-server

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.7 · CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS

• CVE-2020-5251: 0.85% estimated exploitation activity in the next 30 days; percentile 58.17 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

1. you can fetch all the users' objects, by using regex in the NoSQL query. Using the NoSQL, you can use a regex on sessionToken ("SessionToken":{"$regex":"r:027f"}} and find valid accounts this way. Using this method, it's possible to retrieve accounts without interaction from the users. GET /parse/users/me HTTP/1.1 When trying it with an update query the same thing luckily doesn't seem to work: POST /parse/classes/User/PPNk59jPPZ 2. There is another similar vulnerability in verify email and the request password reset. If you sign up with someone else's email address, you can simply use regex in the token param to verify the account: http://localhost:1337/parse/apps/kickbox/verifyemail?token[$regex]=a&username=some@email.com The same thing can be done for reset password: http://localhost:1337/parse/apps/kickbox/requestpasswordreset?token[$regex]=a&username=some@email.com You may need to do it a few times with a different letter/number, but as long as the tokens contain the character…

Published by the source

4 Mar 2020, 20:20 UTC

Last modified by the source

8 Jul 2026, 06:28 UTC

Source last checked

26 Oct 2026, 12:07 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-h4mf-75hf-67w4

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-h4mf-75hf-67w4

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# Patch Next advisory brief: CVE-2020-5251

Advisory: Information disclosure in parse-server
IDs: CVE-2020-5251, GHSA-h4mf-75hf-67w4
Record: https://patchnext.com/advisories/cve-2020-5251 (revision 2, source checked 26 Oct 2026, 12:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: parse-server 4.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm parse-server: affected <= 4.0.0; fixed in 4.1.0

## Suggested inspection (read-only)
- `npm ls parse-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on parse-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-h4mf-75hf-67w4 (OSV record GHSA-h4mf-75hf-67w4 lists affected ranges: npm parse-server >=0 <4.1.0 (fixed))
- Verified: https://github.com/advisories/GHSA-h4mf-75hf-67w4 (GitHub-reviewed advisory GHSA-h4mf-75hf-67w4 lists affected ranges: npm parse-server >=0 <=4.0.0)

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